Hi,
ZWCAD 2009 is now released and it's fully compatible with acad (full, not just LT), up to dwg 2009. It comes in 2 flavours Std @ £390 and Pro £480 (UK prices). Pro has 2d & 3d design support, Std just has 2d design, but can view 3d files. If you know acad you can use zwcad, no retraining required. Get a free download from http://www.zwcad.org.uk.